Video calls require high-rate and low-delay voice and video transmission. It is challenging to deliver high-quality video telephony to end-consumers through the best-effort Internet, especially over wireless links. In this talk, we present our measurement study on several video call systems: FaceTime, Google+, iChat, and Skype. Through a series of carefully designed passive and active measurements, we are able to unveil important information about their design choices and performance, including application architecture, video generation and adaptation schemes, loss recovery strategies, end-to-end voice and video delays, resilience against bursty losses. Obtained insights can be used to guide the design of applications that call for high-rate and low-delay data transmissions under a wide range of “best-effort” network conditions.

Bio:

Yong Liu is an associate professor at the Electrical and Computer Engineering department of the Polytechnic Engineering School of New York University. He received his Ph.D. degree from Electrical and Computer Engineering department at the University of Massachusetts, Amherst, in May 2002. His current research directions include Peer-to-Peer systems, overlay networks, network measurement, online social networks, and recommender systems.He is a member of IEEE and ACM and is currently serving as an associate editor for IEEE/ACM Transactions on Networking, and Elsevier Computer Networks Journal. He is the winner of the Best Paper Award of ACM/USENIX Internet Measurement Conference (IMC) 2012, the National Science Foundation Career Award in 2010, the Best Paper Award of IEEE Conference on Computer Communications (INFOCOM) in 2009, and the IEEE Communication Society Multimedia Communications Best Paper Award in 2008. More information about him is available at: http://eeweb.poly.edu/faculty/yongliu/